Choose Google: Gemini 3.1 Pro Preview if…
- you need built-in web search — to answer from live web results; Meta: Muse Spark Open does not advertise it
Google: Gemini 3.1 Pro Preview vs Meta: Muse Spark Open
Neither wins outright: Google: Gemini 3.1 Pro Preview is the pick when you need built-in web search, Meta: Muse Spark Open when cost matters at scale.
Key numbers
| Spec | Google: Gemini 3.1 Pro Preview | Meta: Muse Spark Open |
|---|---|---|
| Provider | Meta | |
| Input price (per 1M tokens) | $2.00 | $1.25 |
| Output price (per 1M tokens) | $12.00 | $4.25 |
| Blended price (3:1 input/output) | $4.50 | $2.00 |
| Cheaper than … of all models we track | 12% | 25% |
| Context window | 1.0M tokens (~1,573 pages) | 1.0M tokens (~1,573 pages) |
| Larger context than … of all models | 81% | 81% |
| Max output per response | 66K tokens (~49,200 words) | 944K tokens (~707,800 words) |
| Input types | audio, file, image, text, video | text, image, video, file, audio |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2026-02-19 | 2026-10-15 |
What it costs for real workloads
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
| Workload (per month) | Google: Gemini 3.1 Pro Preview | Meta: Muse Spark Open | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $390 | $179 | Meta: Muse Spark Open saves $211 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $360 | $193 | Meta: Muse Spark Open saves $168 |
| Coding / tool-using agent 2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens) | $384 | $201 | Meta: Muse Spark Open saves $183 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $232 | $126 | Meta: Muse Spark Open saves $106 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $112 | $66.75 | Meta: Muse Spark Open saves $45.25 |
Capabilities side by side
| Capability | Google: Gemini 3.1 Pro Preview | Meta: Muse Spark Open | What it lets you do |
|---|---|---|---|
| Tool / function calling | ✓ Yes | ✓ Yes | call your APIs and run agent loops |
| Structured output (JSON schema) | ✓ Yes | ✓ Yes | return JSON that validates against your schema |
| Reasoning / thinking mode | ✓ Yes | ✓ Yes | spend extra tokens thinking before answering hard problems |
| Image input | ✓ Yes | ✓ Yes | read screenshots, charts and scanned pages |
| Audio input | ✓ Yes | ✓ Yes | take speech or audio directly |
| File / PDF input | ✓ Yes | ✓ Yes | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | ✓ Yes | — | answer from live web results |
| Seed (reproducible sampling) | ✓ Yes | ✓ Yes | repeat a generation for tests and evals |
| Log-probabilities | — | ✓ Yes | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
- Google: Gemini 3.1 Pro Preview: price unchanged since we started tracking it on 2026-03-10.
- Meta: Muse Spark Open: price unchanged since we started tracking it on 2026-10-16.
Which should you choose?
Choose Meta: Muse Spark Open if…
- cost matters at scale — it is 56% cheaper on a typical 3:1 input/output mix ($179 vs $390 a month for 50,000 support chats)
- you need log-probabilities — to read token confidence for classification and scoring; Google: Gemini 3.1 Pro Preview does not advertise it
- you generate long outputs in one go — up to 944K tokens (about 707,800 words) per response
- you want the newer model — released 2026-10-15, 8 months after the other
Frequently asked questions
Is Google: Gemini 3.1 Pro Preview better than Meta: Muse Spark Open?
Neither wins outright: Google: Gemini 3.1 Pro Preview is the pick when you need built-in web search, Meta: Muse Spark Open when cost matters at scale. In short: Google: Gemini 3.1 Pro Preview when you need built-in web search; Meta: Muse Spark Open when cost matters at scale, you need log-probabilities, you generate long outputs in one go, you want the newer model.
Which is cheaper, Google: Gemini 3.1 Pro Preview or Meta: Muse Spark Open?
Meta: Muse Spark Open is cheaper: $2.00 vs $4.50 per 1M tokens at a typical 3:1 input/output mix, 56% less. For 50,000 support conversations a month that is $179 against $390.
How much do Google: Gemini 3.1 Pro Preview and Meta: Muse Spark Open cost per million tokens?
Google: Gemini 3.1 Pro Preview costs $2.00 per 1M input tokens and $12.00 per 1M output tokens; Meta: Muse Spark Open costs $1.25 input and $4.25 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, Google: Gemini 3.1 Pro Preview or Meta: Muse Spark Open?
Both take 1.0M tokens per request — roughly 1,573 pages of text.
Do Google: Gemini 3.1 Pro Preview and Meta: Muse Spark Open support function calling and JSON output?
Tool calling — Google: Gemini 3.1 Pro Preview: yes, Meta: Muse Spark Open: yes. JSON-schema structured output — Google: Gemini 3.1 Pro Preview: yes, Meta: Muse Spark Open: yes.
Can Google: Gemini 3.1 Pro Preview or Meta: Muse Spark Open read images?
Yes, both accept image input.
Is Google: Gemini 3.1 Pro Preview or Meta: Muse Spark Open free to use?
No free variant is listed for either; both are pay-per-token.
What is the maximum output length of Google: Gemini 3.1 Pro Preview and Meta: Muse Spark Open?
Google: Gemini 3.1 Pro Preview can write up to 66K tokens (about 49,200 words) per response; Meta: Muse Spark Open up to 944K (about 707,800 words).
When were Google: Gemini 3.1 Pro Preview and Meta: Muse Spark Open released?
Google: Gemini 3.1 Pro Preview was listed on 2026-02-19; Meta: Muse Spark Open on 2026-10-15.
About the two models
Google: Gemini 3.1 Pro Preview
Gemini 3.1 Pro Preview is Google’s frontier reasoning model, delivering enhanced software engineering performance, improved agentic reliability, and more efficient token usage across complex workflows. Building on the multimodal foundation...
Full Google: Gemini 3.1 Pro Preview specs →Meta: Muse Spark Open
Muse Spark Open is a coding-optimized open-weight model. Trained specifically for agentic coding workflows, it delivers higher first-attempt accuracy, reliable tool calling, and deep codebase understanding across the repos developers...
Full Meta: Muse Spark Open specs →